Joel Hodgson will depart Saints this summer after just one season at the club.
The scrum-half, who can also play at 10, has agreed to join Championship outfit Yorkshire Carnegie.
Hodgson moved to Northampton from Newcastle last summer but has made just five appearances this season.
He has found himself behind Kahn Fotuali’i and Lee Dickson in the pecking order.
With Saints signing Tom Kessell from Bristol for next season, Hodgson and Alex Day, who is moving to Cornish Pirates, would have found their game time even more limited.
Hodgson will be joined at Yorkshire Carnegie by Scottish second row Tom Ryder.
The former Glasgow player joined Saints on a short-term deal in January but has only played three games and will move on ahead of next season.
Yorkshire Carnegie head coach Bryan Redpath said: “Joel and Tom are Premiership quality players and I am delighted that they have agreed to join us.
“Joel is a very talented scrum half who can also cover 10 whilst Tom has vast experience, in particular with Saracens and Glasgow.
“Both will be key additions to the players we already have at the club for next season.”